The present invention relates to cationic azo dyes of the general formula I 
where
R1 and R2 are independently hydrogen, nitro, halogen, C1-C6-alkyl,
R3 is hydrogen, C1-C6-alkyl with or without interruption by 1 or 2 nonadjacent oxy, imino, C1-C6-alkylimino groups or by a 
xe2x80x83radical,
A1 and A2 are independently oxy, imino or substituted or unsubstituted C1-C6-alkylimino,
B1 and B2 are independently C1-C6-alkylene with or without interruption by 1 or 2 nonadjacent oxy, imino, substituted or unsubstituted C1-C6-alkylimino groups or by a 
xe2x80x83radical,
Anxe2x8ax96is the equivalent of an anion,
n is 1, and
K is the radical of a coupling component or the radical of a monoazo dye of the formula 
xe2x80x83where
R4xe2x80x2 and R5xe2x80x2 are independently hydroxyl, amino, morpholino or mono- or di(C1-C6)alkylamino, whose alkyl radicals are unsubstituted or substituted by hydroxyl, amino, cyano, C1-C6-alkoxycarbonyl, carbamoyl or mono- or di(C1-C6)alkylcarbamoyl and uninterrupted or interrupted by oxy, and
Q1, Q2 and Q3 are independently hydrogen, C1-C10-alkyl with or without interruption by from 1 to 4 nonadjacent oxy, imino and substituted or unsubstituted C1-C4-alkylimino groups and with or without hydroxyl, halogen or phenyl substitution, or Q1 and Q2 combine with the linking nitrogen atom to form a 5- or 6-membered heterocyclic radical which optionally contains nitrogen or oxygen as further hetero atom,
and additionally n is from 2 to 8 when K is the radical of a coupling component of the formula IIIaxe2x80x2
xe2x80x83where
R6xe2x80x2, is hydrogen, C1-C6-alkoxy with or without oxy interruption in its alkyl radical, mono- or di(C1-C6)alkylamino, C1-C6-alkoxycarbonyl, carbamoyl, mono- or di(C1-C6)alkylcarbamoyl, sulfamoyl, mono- or di(C1-C6)alkylsulfamoyl,
processes for their preparation, their use for dyeing and printing natural or synthetic substrates and also their mixtures.
DE-A-2 218 645 describes water-insoluble trisazo pigments which are monoazo dyes linked via triethanolamine.
DE-A-2 160 590 describes anthranilic acid derivatives bridged with a diethanolamine via the ester group. These diamines are useful for preparing polyurethanes.
It is an object of the present invention to provide novel dyes which have advantageous application properties, especially high affinities for the substrates used, and also good fastness to bleeding and lightfastness.
We have found that this object is achieved by the dyes of the formula I which are defined at the beginning.
Alkyl and alkylene appearing in the abovementioned formula may be straight-chain or branched.
Substituted alkyl appearing in the abovementioned formula may have as substituents for example hydroxyl and methoxy. The number of substituents in the substituted alkyl is generally 1 or 2.
Q1 and Q2 combining with the joining nitrogen atom to form a 5- or 6-membered heterocyclic radical which optionally contains nitrogen or oxygen as further hetero atom may be saturated radicals such as pyrrolidinyl, piperidinyl, morpholinyl, piperazinyl with or without methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, 2-hydroxyethyl or 2- or 3-hydroxypropyl substitution on the nitrogen. Further possibilities are unsaturated radicals such as pyrrolyl, pyrazolyl, oxazolyl, isooxazolyl or imidazolyl with or without methyl, ethyl, propyl or butyl substitution in 2- and/or 4-position or N-3(C1-C4)alkylimidazolyl with or without methyl, ethyl, propyl or butyl substitution in 2- and/or 4-position.
Halogen is fluorine, chlorine or bromine.
R1, R2, R3, Q1, Q2 and Q3 are each for example methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl or 2-methylpentyl.
R3, Q1, Q2 and Q3 may each also be for example 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl, 2- or 3-methoxypropyl, 2- or 3-ethoxypropyl, 2- or 3-propoxypropyl, 2- or 4-methoxybutyl, 2- or 4-ethoxybutyl, 3,6-dioxaheptyl, 3,6-dioxaoctyl, 3,7-dioxaoctyl, 4,7-dioxaoctyl, N,N-dimethylaminoethyl, N,N-diethylaminoethyl, 3-(N,N-dimethylamino)propyl, 3-(N,N-diethylamino)propyl, 2-methylaminoethyl, 2-ethylaminoethyl, 3-propylaminoethyl, 2- or 3-methylaminopropyl, 2- or 3-ethylaminopropyl or 2- or 3-propylaminopropyl.
Q1, Q2 and Q3 may each also be for example heptyl, octyl, 2-ethylhexyl, isooctyl, nonyl, isononyl, decyl (the above designations isooctyl, isononyl and isodecyl are trivial names derived from the alcohols obtained by the oxo process - cf. Ullmanns Encyklopxc3xa4die der technischen Chemie, 4th edition, volume 7, pages 215 to 217, and also volume 11, pages 435 and 436), 2-hydroxyethyl, 2- or 3-hydroxypropyl, 2- or 4-hydroxybutyl, 2-chloroethyl, 2- or 3-chloropropyl, 2- or 4-chlorobutyl, benzyl, 1- or 2-phenylethyl, 2- or 3-butoxypropyl, 2- or 4-propoxybutyl, 4,8-dioxadecyl, 3,7-dioxanonyl, 4,7-dioxanonyl, 2- or 4-butoxybutyl, 3,6,9-trioxadecyl, 3,6,9-trioxaundecyl, 3,6,9-trioxadodecyl, 3,6,9,12-tetraoxatridecyl, 3,6,9,12-tetraoxatetradecyl, 4-hydroxy-2-methyl-3-azabutyl, 4-hydroxy-3-hydroxymethyl-2-methyl-3-azabutyl, 5-hydroxy-2-methyl-3-azapentyl, 5-hydroxy-3-(2-hydroxy-ethyl)-2-methyl-3-azapentyl, 8-hydroxy-2-methyl-3-aza-6-oxaoctyl, 11-hydroxy-2-methyl-3-aza-6,9-dioxaundecyl, 8-hydroxy-(5-hydroxy-3-oxapentyl)-2-methyl-3-aza-6-oxaoctyl or 11-hydroxy-3-(8-hydroxy-3,6-dioxaoctyl)-2-methyl-3-aza-6,9-dioxaundecyl, N,N-dipropylaminoethyl, N,N-dibutylaminoethyl,3-(N,N-dipropylamino)propyl or 3-(N,N-dibutylamino)propyl.
A is for example methylimino, ethylimino, propylimino, isopropylimino, butylimino, isobutylimino, sec-butylimino, tert-butylimino, pentylimino, isopentylimino, neopentylimino, tert-pentylimino, hexylimino or 2-methylpentylimino.
B1 and B2 are each for example methylene, ethylene, 1,2- or 1,3-propylene, 1,2-, 2,3- or 1,4-butylene, (CH2)2O(CH2)2, (CH2)3O(CH2)2, (CH2)3O(CH2)3, (CH2)2O(CH2)2O(CH2)2, (CH2)2NH(CH2)2, (CH2)3NH(CH2)2, (CH2)2NH(CH2)2NH(CH2)2, 
Anxe2x8ax96, the equivalent of an anion, is derived for example from the following anions: fluoride, chloride, bromide, iodide, sulfate, phosphate, formate, acetate, propionate, mono-, di- or trichloroacetate, lactate, methoxyacetate, citrate, succinate, methanesulfonate, benzenesulfonate, 2- or 4-methylbenzenesulfonate or naphthalenesulfonate.
Suitable coupling components KH are compounds of the benzene, naphthalene, quinolene, pyridone, barbituric acid or pyrazolone series and correspond for example to the compounds of the formulae III a-f 
where
R4 is hydroxyl, amino, morpholino, mono- or di(C1-C6)alkylamino whose alkyl radicals are unsubstituted or substituted by hydroxyl, amino, cyano, C1-C6-alkoxycarbonyl, carbamoyl or mono or di(C1-C6)alkylcarbamoyl and are uninterrupted or interrupted by oxy or is C1-C6-alkoxy,
R5 is hydrogen, C1-C6-alkyl or R4,
R6 is hydrogen, C1-C6-alkyl, C1-C6-alkoxy with or without oxy interruption in its alkyl radical, mono or di(C1-C6)alkylamino, C1-C6-alkoxycarbonyl, carbamoyl, mono or di(C1-C6)alkylcarbamoyl whose alkyl radicals are unsubstituted or substituted by hydroxyl or amino and are uninterrupted or oxy interrupted, sulfamoyl, mono or di(C1-C6)alkylsulfamoyl whose alkyl radicals are unsubstituted or hydroxyl or amino substituted and uninterrupted or oxy interrupted, or is carboxyl,
R7 is hydroxyl, amino, mono or di(C1-C12)alkylamino, cyclohexylamino,
R8 is hydrogen, hydroxyl, amino, formylamino, acetylamino, C1-C6-alkyl,
R9 is hydrogen, C1-C6-alkyl, phenyl, hydroxyl, cyano, acetyl, benzoyl, methoxycarbonyl, carbamoyl,
R10 is hydrogen, chlorine, bromine, acetylamino, amino, nitro, sulfamoyl, methylsulfonyl, phenylsulfonyl, C1-C4-alkoxycarbonyl, C1-C4-alkanoyl, benzoyl, carbamoyl, cyano, N-methylimidazolyl, pyridinio,
R11 is hydrogen, C1-C6-alkyl with or without phenyl, hydroxyl, amino, C1-C6-alkoxy, acetylamino, benzoylamino or cyano substitution, cyclohexyl, phenyl with or without benzoylamino, acetylamino, methyl, methoxy, cyano or chlorine substitution, or amino which is substituted by phenyl, C1-C6-alkyl, C1-C6-alkanoyl or benzoyl,
R12 or R13 are independently hydrogen or C1-C6-alkyl,
R14 is methyl, C1-C4-alkoxycarbonyl or phenyl,
R15 is hydrogen, C1-C6-alkyl, cyclohexyl, benzyl or phenyl which is unsubstituted or from singly to triply substituted by fluorine, chlorine, bromine, C1-C4-alkyl, C1-C4-alkoxy, cyano, acetyl, acetylamino, hydroxyl, sulfamoyl or carbamoyl.
R4, R6 and R7 are each for example mono- or dimethylamino, mono- or diethylamino, mono- or dipropylamino, mono- or diisopropylamino, mono- or dibutylamino, mono- or dipentylamino, mono- or diisopentylamino, mono- or dineopentylamino, mono- or dihexylamino, mono- or di-2-methylpentylamino, N-methyl-n-butylamino, N-ethyl-n-butylamino.
R4 may also be for example mono- or di(2-hydroxyethyl)amino, mono-or di(2-hydroxypropyl)amino, mono- or di(3-hydroxypropyl)amino, N-methyl-2-hydroxyethylamino, N-methyl-2-hydroxypropylamino, N-methyl-3-hydroxypropylamino, N-ethyl-2-hydroxyethylamino, N-ethyl-2-hydroxypropylamino, N-ethyl-3-hydroxypropylamino, N-propyl-2-hydroxyethylamino, N-propyl-2-hydroxypropylamino, N-propyl-3-hydroxypropylamino, N-isopropyl-2-hydroxyethylamino, -2-hydroxypropylamino, -3-hydroxypropylamino, mono- or di(2-aminoethyl)amino, mono- or di(2-aminopropyl)amino, mono- or di(3-aminopropyl)amino, mono- or di(2-aminobutyl)amino, mono- or di(4-aminobutyl)amino, 2-cyanoethylamino, 2-cyano-2-methylethylamino, 2-methoxycarbonylethylamino, 2-methoxycarbonyl-2-methylethylamino, 2-ethoxycarbonylethylamino, 2-ethoxycarbonyl-2-methylethylamino, 2-propoxycarbonylethylamino, 2-propoxycarbonyl-2-methylethylamino, 2-isopropoxycarbonylethylamino, 2-isopropoxycarbonyl-2-methylethylamino, 2-butoxycarbonylethylamino, 2-butoxycarbonyl-2-methylethylamino, 2-carbamoylethylamino, 2-carbamoyl-2-methylethylamino, 2-mono or dimethylaminocarbonylethylamino, 2-mono or dimethylaminocarbonyl-2-methylethylamino, mono or di(2-methoxyethyl)amino, mono or di(2-methoxypropyl)amino, mono-or di(3-methoxypropyl)amino, or mono or di(2-hydroxyethyloxyethyl)amino.
R5, R6, R8, R9, R11, R12, R13 and R15 are each for example methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl or 2-methylpentyl.
R11 is hydroxy-C1-C4-alkyl such as hydroxymethyl, 1-hydroxyeth-1-yl, 2-hydroxyeth-1-yl, 1-hydroxy-prop-1-yl, 2-hydroxyprop-1-yl, 3-hydroxyprop-1-yl, 1-hydroxy-prop-2-yl, 2-hydroxyprop-2-yl, 1-hydroxybut-1-yl, 2-hydroxybut-1-yl, 3-hydroxybut-1-yl, 4-hydroxybut-1-yl, 1-hydroxybut-2-yl, 2-hydroxybut-2-yl, 1-hydroxybut-3-yl, 2-hydroxybut-3-yl, 1-hydroxy-2-methyl-prop-3-yl, 2-hydroxy-2-methyl-prop-3-yl, 3-hydroxy-2-methyl-prop-3-yl, 2-hydroxymethyl-prop-2-yl, cyanomethyl, cyanoethyl, cyanopropyl or cyanobutyl.
R11 may also be for example benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylprop-1-yl, 2-phenylprop-1-yl, 3-phenylprop-1-yl, 1-phenylbut-1-yl, 2-phenylbut-1-yl, 3-phenylbut-1-yl, 4-phenylbut-1-yl, 1-phenylbut-2-yl, 2-phenylbut-2-yl, 3-phenylbut-2-yl, 4-phenylbut-2-yl, 1-(phenylmethyl)-eth-1-yl, 1-(phenylmethyl)-1-(methyl)-eth-1-yl, 1-(phenylmethyl)-prop-1-yl, preferably benzyl and 2-phenylethyl, methoxymethyl, ethoxymethyl, n-propoxymethyl, (1-methylethoxy)methyl, n-butoxymethyl, (1-methylpropoxy)methyl, (2-methylpropoxy)methyl, (1,1-dimethylethoxy)methyl, 2-(methoxy)ethyl, 2-(ethoxy)ethyl, 2-(n-propoxy)ethyl, 2-(1-methoxyethoxy)ethyl, 2-(n-butoxy)ethyl, 2-(1-methylpropoxy)ethyl, 2-(2-methylpropoxy)ethyl, 2-(1,1-dimethylethoxy)ethyl, 2-(methoxy)propyl, 2-(ethoxy)propyl, 2-(n-propoxy)propyl, 2-(1-methylethoxy)propyl, 2-(n-butoxy)propyl, 2-(1-methylpropoxy)propyl, 2-(2-methylpropoxy)propyl, 2-(1,1-dimethylethoxy)propyl, 3-(methoxy)propyl, 3-(ethoxy)propyl, 3-(n-propoxy)propyl, 3-(1-methylethoxy)propyl, 3-(n-butoxy)propyl, 3-(1-methylpropoxy)propyl, 3-(2-methylpropoxy)propyl, 3-(1,1-dimethylethoxy)propyl, 2-(methoxy)butyl, 2-(ethoxy)butyl, 2-(n-propoxy)butyl, 2-(1-methylethoxy)butyl, 2-(n-butoxy)butyl, 2-(1-methylpropoxy)butyl, 2-(2-methylpropoxy)butyl, 2-(1,1-dimethylethoxy)butyl, 3-(methoxy)butyl, 3-(ethoxy)butyl, 3-(n-propoxy)butyl, 3-(1-methylethoxy)butyl, 3-(n-butoxy)butyl, 3-(1-methylpropoxy)butyl, 3-(2-methylpropoxy)butyl, 3-(1,1-dimethylethoxy)butyl, 4-(methoxy)butyl, 4-(ethoxy)butyl, 4-(n-propoxy)butyl, 4-(1-methylethoxy)butyl, 4-(n-butoxy)butyl, 4-(1-methylpropoxy)butyl, 4-(2-methylpropoxy)butyl or 4-(1,1-dimethylethoxy)butyl.
R10 is for example formyl, acetyl, propionyl, butyryl or isobutyryl.
R6 is for example mono- or dimethylcarbamoyl, mono- or diethylcarbamoyl, mono- or dipropylcarbamoyl, mono- or dibutylcarbamoyl, mono- or dipentylcarbamoyl or mono- or dihexylcarbamoyl.
R4 and R6 may each be for example methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, isobutoxy or tert-butoxy.
R6 may also be for example methoxyethyloxy, methoxypropyloxy, ethoxyethyloxy, ethoxypropyloxy or propoxypropyloxy.
R15 is for example 2-, 3- or 4-fluorophenyl, 2-, 3- or 4-chlorophenyl, 2-, 3- or 4-bromophenyl, 2-, 3- or 4-methylphenyl, 2-, 3- or 4-ethylphenyl, 2-, 3- or 4-methoxyphenyl, 2-, 3- or 4-cyanophenyl, 2-, 3- or 4-hydroxyphenyl, 2-, 3- or 4-acetylphenyl, 2-, 3- or 4-acetylaminophenyl, 2-, 3- or 4-sulfamoylphenyl or 2-, 3- or 4-carbamoylphenyl.
R6, R10 and R14 may each also be for example methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, tert-butoxycarbonyl, pentoxycarbonyl, isopentoxycarbonyl, neopentoxycarbonyl, tert-pentyloxycarbonyl, hexyloxycarbonyl or 2-methylpentyloxycarbonyl.
R6 may also be for example mono- or dimethylsulfamoyl, mono- or diethylsulfamoyl, mono- or dipropylsulfamoyl, mono- or dibutylsulfamoyl.
R11may also be for example aminomethyl, 2-aminoethyl, 2- or 3-aminopropyl, 2- or 4-aminobutyl, acetylaminomethyl, 2-acetylaminoethyl, 2- or 3-acetylaminopropyl, 2- or 4-acetylaminobutyl, benzoylaminomethyl, 2-benzoylaminoethyl, 2- or 3-benzoylaminopropyl, 2- or 4-benzoylaminobutyl, 2-, 3- or 4-benzoylaminophenyl, 2-, 3- or 4-acetylaminophenyl, 2-, 3- or 4-methylphenyl, 2-, 3- or 4-methoxyphenyl, 2-, 3- or 4-cyanophenyl, 2-, 3- or 4-chlorophenyl, phenylamino, methylamino, ethylamino, propylamino, isopropylamino, butylamino, isobutylamino, sec-butylamino, tert-butylamino, acetylamino, propionylamino, butyrylamino, isobutyrylamino, isobutyrylamino, valerylamino, isovalerylamino, pivaloylamino, pentylcarbonylamino or benzoylamino.
In what follows, coupling components KH are recited by way of example. Examples of coupling components of the benzene series are resorcinol, 2- and 4-methylresorcinol, 1,3-phenylenediamine, 3-aminophenol, 4-methyl-3-aminophenol, 5-amino-2-methylphenol, 4-ethyl-3-aminophenol, 3-N,N-diethylaminophenol, 2,4-diaminotoluene, 2,4-dihydroxybenzoic acid, 4-methyl-2-aminophenol, 3-acetaminophenol, 3-amino-4-hydroxybenzenesulfonamide, o-, m- or p-toluidine, o-, m- or p-xylidine, 2,5-dimethoxyaniline, 2-methoxy-5-methylaniline, 3-amino-4-methylacetanilide, 2- or 4-methoxyacetanilide, N-methylaniline, N-methyl-m-toluidine, N-ethylaniline, N,N-diethylaniline, E-ethyl-m-toluidine, N- ( 2-hydroxyethyl) aniline, N,N-dihydroxyethylaniline or N-(2-hydroxyethyl)-m-toluidine.
Coupling components of the naphthalene series are for example 1-naphthylamine, N-phenyl-1-naphthylamine, N-ethyl-1-naphthylamine, N-ethyl-2-naphthylamine, N-phenyl-2-naphthylamine, 1-naphthol, 2-naphthol, 2,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2-hydroxynaphthalene-1-carboxylic acid, 2-hydroxynaphthalene-3-carboxylic acid, methyl 2-hydroxynaphthalene-3-carboxylate or 2-hydroxynaphthalene-3-carboxamide.
Coupling components of the quinoline series are for example 8-hydroxyquinoline, 8-hydroxy-2-methylquinoline, 8-aminoquinoline, 8-amino-2-methylquinoline, 2-hydroxyquinoline and 2,4-dihydroxyquinoline.
Pyridone coupling components are for example 1-ethyl-2-hydroxy-4-methyl-5-carbamoylpyrid-6-one, 1-(2xe2x80x2-hydroxyethyl)2-hydroxy-4-methyl-5-carbamoylpyrid-6-one, 1-phenyl-2-hydroxy-4-methyl-5-carbamoylpyrid-6-one, 1-ethyl-2-hydroxy-4-methyl-5-cyanopyrid-6-one, 1-methyl-2-hydroxy-4-methyl-5-cyanopyrid-6-one, 1-methyl-2-hydroxy-5-acetylpyrid-6-one, 1,4-dimethyl-2-hydroxy-5-cyanopyrid-6-one, 1,4-dimethyl-5-carbamoylpyrid-6-one, 2,6-dihydroxy-4-ethyl-5-cyanopyridine, 2-hydroxy-4-ethyl-5-carbamoylpyrid-6-one or 1-methyl-2-hydroxy-4-methylsulfonylpyrid-6-one.
Examples of suitable coupling components of the barbituric acid series are barbituric acid, dimethylbarbituric acid and diethylbarbituric acid.
Suitable pyrazolone coupling components are for example 3-methyl-or 3-(C1-C4-alkoxycarbonyl)pyrazol-5-ones which, in 1-position, may bear hydrogen, unsubstituted or methyl-, ethyl-, fluorine-, chlorine-, bromine-, methoxy-, ethoxy-, cyano-, acetylamino-, hydroxyl-, carbamoyl- or sulfamoyl-substituted phenyl. Examples are 1-(2xe2x80x2,5xe2x80x2-dichlorophenyl)-3-methylpyrazol-5-one, ethyl 1-phenylpyrazol-5-one-3-carboxylate and ethyl pyrazol-5-one-3-carboxylate.
Preference is given to dyes of the general formula I where R1 and R2 are each hydrogen.
Preference is further given to dyes where A1 and A2 on the one hand and B1 and B2 on the other are each the same radical.
B1 and B2 are each preferably C2-C6-alkylene with or without interruption by oxy or by C1-C6-alkylimino. B1 and B2 are preferably identical.
Coupling components KH are preferably compounds of the formulae IIIa and IIIb. Preference is given in particular to dyes of the general formula IV 
where n is from 1 to 8 and R1, R2, R3, R4, R5, R6, A1, A2, B1, B2 and Anxe2x8ax96are each as defined above. Particular preference is given to coupling components of the formula IIIa where R4 is hydroxyl, amino, mono- or dimethyl- or -ethylamino or mono- or dihydroxyethylamino and R5 and R6 are independently hydrogen, hydroxyl, amino or methyl.
Particular preference is likewise given to coupling components of the formula IIIb where R7 is hydroxyl or amino.
Particular preference is given to the following coupling components: resorcinol, 3-aminophenol, m-phenylenediamine, xcex1- and xcex2-naphthol, m-toluidine and 2,5-dimethylaniline.
Preference is further given to dyes of the formula I where n is 1.
To prepare the dyes of the formula I, an amine of the formula V 
where R1, R2, R3, A1, A2, B1 and B2 are each as defined above, can be conventionally diazotized and coupled with a coupling component KH. The pH is preferably within the range from 2 to 8.
Advantageously, the diazonium salt solution is metered into the solution of the coupling component. It is generally possible to use a single coupling component and also mixtures of a plurality of coupling components, for example so as to shade the hue.
By using coupling components capable of coupling twice it is possible to use the azo coupling reaction to obtain higher molecular weight dyes. These oligomeric dyes are obtainable by azo coupling of 1 mol equivalent of diamine of the formula IV onto from 1 to 2, preferably onto from 1 to 1.5, especially from 1 to 1.2, mol equivalents of a coupling component of the formula IIIaxe2x80x2
where
R4xe2x80x2 and R5xe2x80x2 are independently hydroxyl, amino, morpholino or mono-or di(C1-C6)alkylamino, whose alkyl radicals are unsubstituted or substituted by hydroxyl, amino, cyano, C1-C6-alkoxycarbonyl, carbamoyl or mono- or di(C1-C6)alkylcarbamoyl and uninterrupted or interrupted by oxy, and
R6xe2x80x2 is hydrogen, C1-C6-alkoxy with or without oxy interruption in its alkyl radical, mono- or di(C1-C6)alkylamino, C1-C6-alkoxycarbonyl, carbamoyl, mono- or di(C1-C6)alkylcarbamoyl, sulfamoyl, mono- or di(C1-C6)alkylsulfamoyl.
The coupling step is carried out at a pH above 2, preferably within the range from 3 to 7. The desired pH may be set and, if necessary, corrected during the coupling reaction by adding, for example, ammonium or alkali metal bases, e.g., sodium hydroxide, sodium carbonate, sodium acetate, potassium hydroxide, potassium carbonate or potassium acetate. Usually, the end point of the reaction will be reached not more than 2 hours after completion of the addition. Chain termination is effected by coupling onto a coupling component devoid of a reactive terminus or by decomposing the diazonium compounds.
Depending on the choice of ratio for the starting materials, mixtures are obtained of various oligomers, among which the dimer fraction increases with increasing coupling component fraction. An approximately stoichiometric reaction of 1 mol of diamine V with 2 mol of coupling component IIIaxe2x80x2 provides predominantly the preferred dyes where n is 1. Separation into the individual dyes is possible in principle, but generally unnecessary, since the mixtures are found to have good application properties.
Coupling a diazo component obtained by diazotizing an amine of the formula VI 
onto disazo dyes IV provides likewise preferred tetraazo dyes.
The amines VI are generally known and are described for example EP-A-0 159 549.
The dyes are very useful in the production of pulp-dyed, sized and unsized paper. They are likewise useful for dyeing paper by the dip process.
The dyeing of paper, leather or cellulose takes place according to methods known per se.
The novel dyes and their preparations color the papermaking wastewater only minimally, if at all, which is particularly favorable from the aspect of keeping the water courses clean. They are highly substantive, do not marble on paper and are substantially pH-insensitive. The dyeings on paper are notable for good lightfastness. On prolonged exposure to light the hue changes on-tone.
The basic azo dyes of the formula I of the invention can be used alone, in mixtures with each or one another and together with other cationic or anionic compounds in the form of their solutions or in the form of powders or granules. They are advantageously useful for dyeing or printing polymeric material, especially papery materials such as paper and paperboard, but also cellulose, cotton, leather, bast fibers, hemp, flax, sisal, jute, coir, straw or anionically modified fibers and also in inks, including printing inks.
In relation to the production of dye preparations comprising the novel dyes of the formula I, the use of polymers, such as polyacrylic acids, polyacrylic acid derivatives, polyvinylamines, polyvinylamides, polyvinyl acetates, polyvinyl alcohols, polyvinylpyrrolidones, polysiloxanes or copolymers of the respective monomers, must be emphasized. Similarly, oligomers of ethyleneimine, ethylene oxide or propylene oxide or derivatives thereof can be used.
The dyed papers, which exhibit good bleachability, are wetfast, not only with regard to water, but also with regard to milk, soapy water, sodium chloride solutions, fruit juices or sweetened mineral water, and are also stable to alcoholic drinks because of their good alcohol fastness.
The novel dyes can also be used for dyeing, padding or printing polyacrylonitrile textiles or anionically modified polyamide or polyester textiles.